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View Full Version here: : some questions!


cjpops
24-11-2011, 08:20 AM
I followed a thread here regarding barlow collimating with a orion lasermate deluxe and I believe this method made a huge difference viewing - I'm getting more details of Jupiter.

I'm even seeing Jupiter's cloud details on my cheap 10mm eyepiece attached to a barlow - Will i get much more details using a say, a Televue eyepiece?

I have a Meade 4000 eyepiece kit arriving probably next month sometime and was thinking whether i'll be better off selling them unused to fund a far superior eyepiece (TeleVue?)

There is some sort of movement surrounding Jupiter - is this some sort of atmosphere vibrations? I am viewing it around 9pm near Melbourne (Light pollution?)

Also, it's quite bright - should i use a filter?

Using a Lightbridge 12" by the way

ZeroID
24-11-2011, 09:26 AM
Hi Craig,

I'd say Check out the Meade set before you pass up on them. Won't make any difference to the second hand price regardless and they'll give you a range to choose from, you always need more than one. EP's are always a personal choice so if you can try some out at Star Parties etc before lashing out huge $$$

The movement around Jupiter is usually air turbulence in the seeing. Makes the edges 'boil' and blurs details unfortunately. More prevalent in city\suburban unvirons but weather conditions etc all have a lot to do with it at both local and high altitude. My view lately is back over the CBD so tends to be somewhat messy.

Jupiter is quite bright. I have been using a blue and a yellow filter to help contrast and reduce glare. A neutral density filter might also help, like a moon filter although I haven't tried that option yet. (Mental note to self - must try that )

Cheers
Brent

Paddy
24-11-2011, 04:27 PM
Hi Craig,

Great that you're starting to see more detail on Jupiter. A premium eyepiece is a good investment, but often what you'll really notice is that the bigger FOV of something like a Nagler is the bonus. You won't see a huge amount more detail in the centre of the field although it will be better. If your collimation has been with a laser only, you may find you get more improvement in view for your dollar by investing $60 or so in a Cheshire eyepiece if you don't have one. The laser is good for collimating the angle of the primary and secondary mirrors, but not for getting the position of the secondary just right. So if you haven't already done so, get one and have a play.

As someone with a few premium eps, they are well worth the investment when you know what it is that you want in terms of magnifications, field of view and eye relief and your scope is well set up. Having a look through other people's eyepieces is the best bit of research.

cjpops
24-11-2011, 06:19 PM
Thanks the info Paddy and Brent, i'll have to start going to star parties and see other people's setup - hopefully i can attend snake valley for one evening..

Will try out the filters when my meade set arrives. Will look up Cheshire eyepiece, wasnt aware that the laser method doesnt give accurate collimation - i did get far better results using the barlow method.

Thanks again. :)

barx1963
24-11-2011, 06:53 PM
Try and get to SV if you can, hopefull the weather will be OK!
The laser is really only the final stage in the collimation process. It ios the bit you need to do each night, I only check the other parts every month or so, but you do need to have everything else righ before using the laser.
Have a look at this guide http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide .htm I found it really useful

Malcolm

cjpops
24-11-2011, 09:08 PM
Thanks for the link Malcolm, so much to learn! :D

Is there any specific cheshire eyepiece you guys recommend for a 12" lightbridge?

Edit: is this something i should be looking for: http://www.astroshop.com.au/products/details.asp?id=MAS-050L

Also, how do you guys clean the primary mirror? I've got a bit of surface dust and not sure if i should use a air compressor or some 'special' optic cleaner?

barx1963
24-11-2011, 11:09 PM
No worries Craig
Farpoint make pretty good gear from what I have seen so should be OK.
Think long and hard before cleaning the mirror. A little dust (or even quite a lot of dust!) has only a tiny effect on the optical quality of the mirror, but make a mess of cleaning it and the mirror is permanently damaged unless you get it recoated.
There is an article by Mike here http://www.iceinspace.com.au/63-345-0-0-1-0.html on mirror cleaning but IMHO only do it if it is really filthy.
Also dont use an air compressor as that will simply blow any dirt in the line or on the mirror very hard onto the mirror surface and scratch it. Even those compressed air cans are not a good idea. At the most I would only use one of those bulb blowers you can buy (Bintel sell them) and even then be gentle!!!

Malcolm

cjpops
24-11-2011, 11:22 PM
I better leave the mirror alone then :eyepop: - thanks Malcolm.